If you have a gutters on your house and want an inexpensive way to start using
rainwater for your landscaping needs, rain barrels are a good way to go. We do
not recommend using rain barrels for potable (drinking water) systems.

What you need to get started:

Barrel and fittings

Diverter or another mechanism to get water into the barrel from the gutter

Gravity or a pump for retrieving the water from the barrel

Screening
on both overflow and entry point to keep mosquitoes out. Window screening is small enough. If you are using drip irrigation,
we recommend using a .5 millimeter screen to filter out debris.

Hose for overflow outlet

Mosquito donuts (optional – the screen should be enough to keep mosquitoes out)

What to look for in a barrel:

Barrel should be a dark color to keep light out and prevent

algae growth; we recommend painting the barrel if it is made of polyethylene

If
choosing a recycled barrel, use food-grade barrels or barrels that have not
been used to store chemicals

Screw-on
or locking lid to protect from insects and to prevent children from falling in

Even though they are cheaper, we do not recommend "tight-head" barrels which do not have removable lids because you cannot clean the inside of the barrel

Intake
fitting (for closed/lidded barrel)

Overflow and hose bib
fittings

Hose
bib – should be above the bottom of the barrel to prevent sediment from
clogging the spigot